This Center Grant requests CORE and implementation support for a broadly based program for the study of Mental Retardation and Developmental Disabilities. The scientific basis of the research program rests upon investigation in two major program areas: a) Genetics and b) Neuroscience - Biological Neurogenetics, Developmental Neurology, Cellular Neuroscience, Developmental Neurology, Epilepsy Studies, Ophthalmology. Additional closely related laboratories: Developmental Biology and Endocrinology have been established. Clinical and Behavioral Research is centered in three additional laboratories, i.e., Neuroepidemiology, Clinical Neurophysiology/Behavior, and Neuropsychology and a new program of neonatal neurology clinical research is planned. The multidisciplinary approaches include fields of pediatrics, neurology, neurosurgery, neuropathology, psychiatry and ophthalmology, and the relevant basic science fields of genetics and the various neurosciences. The laboratory program is housed in over 50,000 square feet of the Enders Pediatric Sciences Building. The objective of the program is to provide a scientific and clinical basis for the better understanding of the factors leading to Mental Retardation and Developmental Disabilities, and to apply this information to the prevention of these disorders, and to the management of the handicapped individual.